[Note: This is the second sample from my rough draft of a far
from finished new book, Wild
Free & Happy. I don’t
plan on reviewing more books for a while.
My blog is home to reviews of 196 books, and you are very welcome to
explore them. The Search field on the
right side will find words in the full contents of all rants and reviews, if
you are interested in specific authors, titles, or subjects.]
Our
Tree Critter Ancestors
The dawn of life on Earth began maybe four billion years ago,
with the emergence of single-celled beings, the common ancestors of all forms
of life, including us. Let’s fast
forward to around 65 million years ago, when our first primate ancestors came
into existence, not long after dinosaurs moved off the stage. These critters were squirrel-sized, and lived
high above the ground in the humid tropical rainforests of Mother Africa. They were probably insectivores, furry little
hunters that dined on the delicious flesh of bugs and grubs.
Arboreal (tree-dwelling) primates had little need for a
powerful sense of smell like most terrestrial (ground-dwelling) animals
have. What they needed was excellent
stereoscopic vision, via forward oriented eyes that provided accurate depth
perception, so they could scamper and leap through the branches without
mishap. Being able to perceive colors
made it easier to find ripe fruit, which was a primary food source. Even today, bright red objects attract our
attention.
Their hands and feet evolved into forms fine-tuned for
grasping bark, vines, and branches, with toes and fingers tipped with nails,
not claws. Fingers were long and curved,
wrists freely rotated, and shoulder joints were flexible. An acute sense of touch and a sharp mind
helped them excel at airborne acrobatics.
Humans retain a number of these arboreal traits.
Our ancestors were tree-dwellers for most of the 65 million
year saga of primates. A look in the
mirror shows clear evidence of this heritage.
Most primate species today remain partly arboreal. Humans are the only living primates that are
fully terrestrial. Large male gorillas
do not sleep in the trees, but the other gorillas do.
In the rainforest, food was available year round, so our
ancestors enjoyed an easy life. Living
amidst a cornucopia of organic fruit, nuts, insects, and assorted tree
critters, they could live happily without tools, fire, cooking, cell phones, or
psych meds. The climate was comfortable,
so there was no need for clothing. A
simple tree nest was all they needed. It
was a wonderful way of life, while it lasted.
They only used renewable resources, and they left no permanent scars on
the forest. Like all other animals at
the time, they had a way of life that was genuinely sustainable.
Shift
to the Savannah
Climate change is a trickster that takes great delight in
periodically pulling the rug out from under stable ecosystems, and watching
them scramble to survive. It’s an
exciting roller coaster of hot and cold, wet and dry, calm and stormy. Species that can’t adapt to changing
conditions go extinct, creating opportunities for other species to fill their
ecological niche. The show of life must
go on.
Long, long ago, in Mother Africa, the climate was warm and
moist, home to the magnificent rainforests in which primates evolved. Later, around five million years ago, as
glaciers grew in the Northern Hemisphere, the climate in African rainforests
began to shift to cooler and dryer. By
two million years ago, lush rainforests were far smaller, largely replaced by
expanding savannahs (grasslands with scattered trees). If it wasn’t for climate change, you might be
sitting naked on a branch today, wild, free, and happy in a lush rainforest
paradise, nibbling on fruit with your friends and family, in a clean, healthy,
sustainable world.
As the rainforests shrank, our tree-dwelling ancestors were
something like tadpoles in a puddle that was drying up. Many species of arboreal critters went
extinct, but not all of them. The
ancestors of chimps, bonobos, gibbons, and orangutans were able to remain in
the forest and avoid extinction, while baboons, gorillas, and our ancestors
took a deep breath, moved to the ground, and tried to adapt to a new way of
life.
On the savannah, our early ancestors were weird looking,
funny smelling undocumented immigrants, attempting to survive in a habitat for
which evolution had done little to assist them.
Their limited speed, size, and strength were serious drawbacks. They were newcomers in a grassland
neighborhood where most of the long-term residents had been coevolving for
millions of years. The new neighborhood
included numerous large carnivores that were strong, fast, and equipped with
sharp claws and fangs. They specialized
in weeding out the injured, sick, elderly, immature, and inattentive. Many of our ancestors became organic cat
food.
To survive, our ancestors used several defensive
strategies. They lived in groups, where
many eyes were constantly paying attention to the surroundings. When someone noticed a threat, loud calls
were made to alert the gang, and the predator lost the advantage of surprise. Sometimes they mobbed hungry predators,
aggressively assaulting them. Other
times they quickly scattered in every direction. The ancestors were careful to be as invisible
as possible. They chose sleeping places
that offered the most security. As a
result of their cleverness, luck, and risky choices, an enormous number of
ground-dwelling primates survive today.
Rainforests have high biodiversity, they provide a pleasant
home for huge numbers of species.
Savannahs support far less biodiversity but, unlike dense forests, they
provide excellent habitat for many large animal species. A square mile of rainforest contains tons of
biomass in its trees, far more than a square mile of grassland, but grassland
can produce more new biomass every year, primarily during the wet season. This nutritious vegetation, which includes
high-energy seeds, grows close to the ground, a convenient location for grazing
animals.
The biological productivity of grasslands (savannahs,
prairies, and steppes) encouraged the emergence of large herds of herbivores
and their predators. When our ancestors
moved to the ground, evolution had not equipped them for hunting large game, or
escaping from speedy carnivores. They
had two options, adapt or go extinct.
2 comments:
You should read Elaine Morgan. The aquatic ape theory explains our shift from rainforest to savanna much better than the generally accepted idea that we somehow survived the transition with zero adaptation. Very interesting stuff-looking forward to your book.
Thanks! I'll take c look at it.
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